feat(showcase): add bookshelf

The bookshelf with leaning books was the first unclaimed candidate in
the ROADMAP pool. What an envelope check cannot see on it is whether a
leaning book rests on its neighbour: tipped too far its board cuts the
neighbour's head edge, not far enough it stands in the air, and every
seat, the bounding box and the book-overlap budget (which must exempt
the designed contact) still pass. The piece reads the leaning board's
outer-face plane off the mesh and asserts the neighbour's head edge sits
0.3-2.0 mm behind it; --air-lean and --deep-lean exit 22 on it.

Also asserts both sides on the floor, housed cross members, page blocks
glued into their boards, gilt bands seated on the spine, every book
seated on its shelf or the book below, headroom, size spread, zero
unplanned book overlaps and no right-angle wood edges, each with a
falsifier proven on 4.5.11, 5.1.2 and 5.2.1.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>

Author: TMHSDigital

.cursor-plugin/plugin.json

@@ -171,6 +171,7 @@
     "showcase/brazier",
     "showcase/apothecary-shelf",
     "showcase/wooden-yoke",
-    "showcase/butter-churn"
+    "showcase/butter-churn",
+    "showcase/bookshelf"
   ]
 }

CLAUDE.md

@@ -22,7 +22,7 @@ rules/<rule-name>.mdc          - Anti-pattern rules, 9 total
 templates/<template-name>/     - Starter projects, 3 total
 snippets/<snippet-name>.py     - Standalone code patterns, 27 total
 examples/<name>/               - Runnable smoke-gated examples, 59 total (+ gallery.json)
-showcase/<name>/               - Budget-conformance props, 34 pieces (sibling of examples/; see showcase/README.md)
+showcase/<name>/               - Budget-conformance props, 35 pieces (sibling of examples/; see showcase/README.md)
 scripts/build_gallery.py       - Regenerates docs/gallery/ from examples/gallery.json + showcase/gallery.json
 scripts/site/                  - Vendored landing-page build (Jinja2)
 docs/gallery/                  - Committed generated gallery pages + hero renders

README.md

@@ -18,7 +18,7 @@
 </p>
 
 <p align="center">
-  <strong>16 skills</strong> &nbsp;&bull;&nbsp; <strong>9 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>27 snippets</strong> &nbsp;&bull;&nbsp; <strong>59 examples</strong> &nbsp;&bull;&nbsp; <strong>34 showcase pieces</strong>
+  <strong>16 skills</strong> &nbsp;&bull;&nbsp; <strong>9 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>27 snippets</strong> &nbsp;&bull;&nbsp; <strong>59 examples</strong> &nbsp;&bull;&nbsp; <strong>35 showcase pieces</strong>
 </p>
 
 <p align="center">
@@ -37,7 +37,7 @@
 
 ## Overview
 
-This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 34 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
+This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 35 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
 
 The content is consumed by AI coding agents reading these files directly from a checkout — **there is no MCP server in this repository, and none is required**. Cursor applies `rules/*.mdc` automatically wherever their scope globs match and takes skills by name in chat; Claude Code reads `skills/` and `rules/` from the project workspace, or from this repo kept as a referenced checkout. Any agent that can read files in a workspace can use it the same way. There is no build step for the content — edit the Markdown and Python files directly.
 
@@ -106,7 +106,7 @@ per-script exit-code model, are in
 Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](showcase/README.md).
 
 <details>
-<summary><strong>34 showcase pieces</strong> — click to expand the preview grid</summary>
+<summary><strong>35 showcase pieces</strong> — click to expand the preview grid</summary>
 
 <p align="center">
   <a href="showcase/shipping-crate/"><img src="showcase/shipping-crate/preview.webp" width="24%" alt="Shipping crate: a wooden slat crate with iron corner brackets on a dark studio floor, warm wedge on the back wall" /></a>
@@ -143,6 +143,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
   <a href="showcase/apothecary-shelf/"><img src="showcase/apothecary-shelf/preview.webp" width="24%" alt="Apothecary shelf: a stained wooden shelf unit with an arched crest, gallery rails and three drawers, stocked with labelled glass bottles, flasks and glazed jars, on a dark studio floor" /></a>
   <a href="showcase/wooden-yoke/"><img src="showcase/wooden-yoke/preview.webp" width="24%" alt="Wooden yoke: a carved oak ox yoke with upturned ends standing on two bent hickory oxbows pinned above the beam, with an iron ring hung under its centre, on a dark studio floor" /></a>
   <a href="showcase/butter-churn/"><img src="showcase/butter-churn/preview.webp" width="24%" alt="Butter churn: a tall staved oak churn narrowing toward the top, bound by three iron hoops, with a two-board lid and a maple dasher handle rising through it, on a dark studio floor" /></a>
+  <a href="showcase/bookshelf/"><img src="showcase/bookshelf/preview.webp" width="24%" alt="Bookshelf: a stained wooden bookcase of cloth and leather hardbacks, some standing, some stacked flat and two leaning on their neighbours, on a dark studio floor" /></a>
 </p>
 
 [`shipping-crate`](showcase/shipping-crate/) — procedural crate through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets. Falsifier `--skip-decimate` exits 9.
@@ -209,6 +210,8 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
 
 [`butter-churn`](showcase/butter-churn/) — procedural staved plunge churn whose dasher stroke is recomputed from the inner wall read off the staves and the plunger's reach, through the same pipeline. Falsifiers `--wide-dasher` exits 20, `--tight-hole` exits 18.
 
+[`bookshelf`](showcase/bookshelf/) — procedural bookcase of thirty-eight rounded-spine hardbacks, standing, stacked and leaning, whose leaning books' contact with their neighbour's head edge is recomputed as a band, through the same pipeline. Falsifiers `--air-lean` and `--deep-lean` exit 22, `--crowd-books` exits 23.
+
 </details>
 
 ## Examples

ROADMAP.md

@@ -139,7 +139,8 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo
 - ~~Apothecary shelf (shelf unit, bottles and jars of varied form) as a game-prop showcase piece~~ **SHIPPED** as `showcase/apothecary-shelf/` — housed shelves, gallery rails, lapped back boards, a drawer bank and an arched crest, stocked with fifteen lathed vessels in five forms, each corked or lidded and labelled on its own rings; per-vessel headroom under the member above is read off the mesh, `--tall-flask` exits 20 on it while every seat and the envelope still pass
 - ~~Wooden yoke (oxbow, iron rings) as a game-prop showcase piece~~ **SHIPPED** as `showcase/wooden-yoke/` — lofted oak beam with neck saddles and upturned ends, two bent-hickory bows through it and pinned above it, a staple and a threaded hung ring; each neck opening measured between the bow legs and up to the saddle, `--pinch-bows` exits 19 on it while the bows still ground and the envelope is unchanged
 - ~~Butter churn (staved tub, lid, dasher) as a game-prop showcase piece~~ **SHIPPED** as `showcase/butter-churn/` — sixteen tapered staves with canted ends, three hoops seated vertex-for-vertex on them, a three-board bottom in a croze, a two-board lid and a cross dasher; the plunge stroke is recomputed from the inner wall and the plunger's reach, `--wide-dasher` exits 20 on it while the plunger still clears the staves at rest
-- Bookshelf with leaning books (upright and toppled volumes of varied size, one leaning on its neighbour) as a game-prop showcase piece — the lean needs a contact budget the apothecary shelf's upright vessels never exercised: each leaning book rests on its neighbour's spine edge and on the shelf, not in either
+- ~~Bookshelf with leaning books (upright and toppled volumes of varied size, one leaning on its neighbour) as a game-prop showcase piece~~ **SHIPPED** as `showcase/bookshelf/` — housed shelves on a recessed plinth, lapped back boards and a stepped cornice, thirty-eight rounded-spine hardbacks with glued page blocks and gilt bands, standing, stacked and leaning; each leaning board's contact with its neighbour's head edge is read off the mesh as a plane depth, `--air-lean` and `--deep-lean` exit 22 on it while every seat and the envelope still pass
+- Library ladder or book trolley with loose books as a game-prop showcase piece — books resting across two rails (a ledge, a trolley shelf) exercise a two-point support the bookshelf's flat shelves never do
 - Ox cart tongue or plough beam that hitches to the yoke's ring as a game-prop showcase piece — a hitch is a ring-on-hook contact the yoke's hung ring only tests against a fixed bar
 - ~~Small modular kit showcase on recognizable geometry (`modular-kit-snap` contract)~~ **SHIPPED** as `showcase/fence-kit/` — tiling post-and-rail section (AABB X is the tile width; does not re-witness the snap contract); `--skip-decimate` exits 9 on the LOD1 ratio band